C2 : Translation of extra field to be used in Vue part

[NicoDucou]

In the user profil card on account/home we show extra field of users. Those extra fields can be translated. The translation is added in the .po file but are not included by default in the assets/locales/*.json files.

So we need a process that when we had a translation in the .po files if it's a term that is used in the Vue part it should be added in the assets/locales/en.json file if it does not already exist and then run the command to generate de json files for all the languages : php bin/console chamilo:update_vue_translations